Cancer of the female breast is a significant health matter worldwide. The current treatment of breast cancer includes surgery, chemotherapy and radiation therapy, and combinations of these three modalities. Approximately one-half of the women in the U.S. that are diagnosed with breast cancer will elect or will require a mastectomy. Thus, mastectomy procedures are commonly used for the treatment of breast cancers.
Mastectomies have been performed since the late 1800s, by a procedure technically known as the Halstead radical mastectomy. During this procedure, the breast tissue and the pectoralis major muscle along with a variable amount of skin including the nipple-areolar complex is removed. Typically, an axillary lymph node dissection is performed concurrently with the mastectomy. This procedure leaves the patient with a Halstead radical mastectomy deformity which is disfiguring and can be emotionally traumatic. The deformity is especially disfiguring when skin drafting is required to close the defect.
The Halstead procedure ("radical mastectomy") has been modified by preserving the pectoralis major muscle (a "modified radical mastectomy"), and by reducing the skin excision to allow for direct linear closure of the defect. As discussed below, mastectomy closure is distinct from post-mastectomy breast reconstruction. Mastectomy closure techniques serve merely to close the excision site, not to reconstruct the shape and aesthetics of a breast.
Post-Mastectomy Closure: In the past, mastectomy closure techniques have included split thickness skin grafts attached directly to the rib cage, in the context of a Halstead radical mastectomy; or simple straight line closure of an elliptical skin excision.
Closure of the skin defect could also involve the immediate incorporation of a cutaneous or myocutaneous tissue flap to at least partially replace the excised tissue. Myocutaneous units are commonly used to cover defects, whether traumatic or post-resectional. Myocutaneous units were prepared as a combination of both skin and muscle, or as a muscle units that subsequently were skin grafted. Myocutaneous units were transferred as free flaps (flaps detached from intrinsic blood supply), thereafter connecting the unit's axial blood supply to recipient vessels near the defect.
Latissimus dorsi or rectus abdominis myocutaneous flaps were the most frequently utilized myocutaneous flaps for post-mastectomy closure. Some common closure applications for latissimus dorsi flaps include coverage of defects in the head and neck area, especially defects created from major head and neck cancer resection; additional applications include coverage of chest wall defects other than mastectomy deformities. The latissimus dorsi was also used as a reverse flap, based upon its lumbar perforators, to close congenital defects of the spine such as spina bifida or meningomyelocele.
To affect post-mastectomy closure, a latissimus dorsi myocutaneous flap procedure was first combined with the Halstead mastectomy by Dr. Iginio Tansini in Italy in 1906. (Maxwell: Iginio Tansini and the Origin of the Latissimus Dorsi Musculocutaneous Flap, Plastic and Reconstructive Surgery (1980) 65(5):686-692) As illustrated in FIG. 1, a latissimus dorsi myocutaneous flap having a cutaneous paddle P, was used to close the mastectomy defect. This myocutaneous flap had an intrinsic axial blood supply that was critical to the transfer and survivability of the flap.
Prior to the development of the Tansini procedure, random cutaneous flaps had limited survivability due to the paucity of their blood supply. The Tansini procedure did not, however, result in breast reconstruction. The flap was used only to close the chest wall defect.
Post-Mastectomy Breast Reconstruction: Due to the adverse characteristics of a mastectomy deformity, either from a radical mastectomy or a modified radical mastectomy, many women opt for post-mastectomy breast reconstruction. Reconstruction can take place contemporaneously with the mastectomy, or at a later time.
To achieve breast reconstruction, it is common to use a submuscular breast expander or a permanent implant in conjunction with some form of a mastectomy closure technique. A breast expander allows for, and generally requires, sequential addition of fluid to stretch the remaining breast tissue. Accordingly, expanders or implants ("breast inserts") are inserted beneath the mastectomy incision, and have been used as a method for either immediate or delayed breast reconstruction.
Post-Mastectomy Use of Myocutaneous Flaps: There are several disadvantages to post-mastectomy use of former myocutaneous flaps, in the context of excision closure or of post-surgical breast reconstruction. In either of these contexts, most procedures cause a significant transverse scar across the chest. Transverse double tier scarring Ts is illustrated, for example in FIG. 1. The donor site scar on the back is also substantial. When such procedures are used and a breast is reconstructed, the disadvantages are exacerbated since there is a large elliptical paddle of skin across the breast. This skin paddle has different pigmentation than the adjacent breast skin. Furthermore, the large flap of skin does not adequately recreate the contour of the breast.
Circumareolar Mastectomy: Previously, major resections of skin occurred during radical or modified radical mastectomy procedures. More recently, skin resection has been limited to the nipple-areolar complex, through a circumareolar or periareolar incision. Modified radical mastectomies with circumareolar incisions have been performed on patients who did not have pre-existing invasion of the surrounding breast skin. When the skin excision is limited to the region of the nipple-areolar complex, the skin envelope of the breast is preserved.
When a circumareolar mastectomy was performed via an excision of the nipple-areolar complex, a straight line closure with insertion of breast expander has been used. (Grossman et al.: An Alternative Technique for Modified Radical Mastectomy with Immediate Reconstruction. Contemp. Surg. (1991) 38(6):20-24) Thus, with this form of post-mastectomy reconstruction the incision was closed with a straight line closure. Consequently, the reconstructed breast was skin deficient in comparison to the contralateral breast. This tissue shortage frequently required a repositioning surgery of the contralateral breast, resulting in scarring on the contralateral breast and on the ipsilateral breast. Moreover, the reconstructed breast lacked any nipple-areolar complex.
Trans-rectus abdominis muscle flaps (TRAM flaps) have also been used in combination with a circumareolar mastectomy. TRAM flaps have served to close a mastectomy defect and to provide breast reconstruction. With the TRAM flap, a circular skin island is designed and transferred to the mastectomy defect. In some instances, a nipple-areolar reconstruction was performed. This skin island did not result in a reconstructed breast having a nipple-areolar complex with the same projection as a normal breast. In a TRAM flap procedure, the subcutaneous tissue of the flap, rather than a breast implant, fills the void left by the removal of the breast tissue. As with other myocutaneous flaps, projection of the nipple-areolar complex was poor. The subcutaneous tissue is primarily adipose tissue; the transferred rectus abdominis muscle functions princi ply as a conduit of the vascular supply. Rather, the majority of the reconstructed breast volume was filled by adipose subcutaneous tissue of the TRAM myocutaneous unit.
A physician and patient must weigh a number of issues when contemplating use of a TRAM flap. The flap loss rate is higher with TRAM flaps as compared to latissimus dorsi flaps, because the circulation of the myocutaneous unit is less reliable. Heretofore, a nipple-areolar reconstruction with circulation sufficient to support harvesting and regrafting of the patient's own areola was not possible due to the poor blood supply with former TRAM flaps. Moreover, there is no reported literature documenting successful contemporaneous post-mastectomy TRAM flap breast reconstruction to provide a breast with-a nipple-areolar complex. Since subcutaneous adipose tissue provides the majority of the reconstructed breast volume with former TRAM flaps, fat necrosis of this tissue was a significant complication with this procedure. If fat necrosis of the adipose tissue occurs, calcifications and connective tissue masses can result. These sequelae can further exacerbate the difficulty of diagnosing a chest wall cancer recurrence, and diminish the quality of the reconstructed breast.
The donor site scar can be an issue with the TRAM procedure: the scar is located on the lower abdomen and runs hip to hip. Patients may be subject to abdominal wall weakness and hernia formation after one or two rectus muscles are transferred to the breast. The TRAM flap procedure can be performed only once. Breast reconstruction for any subsequent breast cancer would require the use of a different technique. Use of a TRAM flap is limited if the woman has any abdominal scars or if the woman has an inadequate amount of subcutaneous tissue. These limiting issues with a TRAM flap were especially problematic when attempting to reconstruct a large breast. However, some women prefer a TRAM procedure, it can often achieve breast reconstruction without use of an implant, and it can serve as abdominoplasty if a woman has excess abdominal tissue.
Former free gluteal flaps have also been designed which function in a similar fashion to the former TRAM flap. The former gluteal flap has the same disadvantages as the former TRAM flap, as well as the disadvantages typically attendant to free flaps.
In general, there are several significant drawbacks with prior breast reconstruction procedures when used after a standard modified radical mastectomy. Severe scarring is one of the most serious problems. Due to the substantial contour distortion produced by these techniques, a reliable method of immediate and total breast reconstruction could not be performed, since it was difficult to determine where the nipple-areolar complex should be placed in a one-stage procedure. Moreover, repositioning of the contralateral breast was often required, consequent to the limited amount of tissue available for reconstruction on the mastectomy side. Thus, at best, multiple stage breast reconstruction procedures were necessary. Each subsequent procedure carried additional surgical risks, such as infection, bleeding, and anesthetic complications. After a breast was reconstructed, the breast had a distinctly artificial appearance due to the large amounts of skin resection and scarring.